create database if not exists xuexiao default charset=utf8;
use  xuexiao;
create table studentInfo (
 `name` varchar(10),
 sex char,
 age int,
 address  varchar(10)
 
);
show tables;
-- 插入數(shù)據(jù)
insert into studentInfo (`name`, sex,age,address) values ('zhangsan' , '男' ,18,"河南省許昌市");
select *from studentinfo;  -- 打印
--  要插入的數(shù)據(jù)順序和創(chuàng)建表格的數(shù)據(jù)順序相同鹿霸，則字母可以省略
insert into studentInfo values ('李四' , '女' , 20 , "河南省安陽市");
--  要插入的數(shù)據(jù)順序和創(chuàng)建表格的數(shù)據(jù)順序不同，則字段不可以省略挎峦，要求一一對應(yīng)
insert into studentinfo (sex , address , age , `name`) values ('男',"美國拉斯維加斯" , 18,'安德伍德');
insert into studentinfo (`name`) values ('小愛' ); -- 沒有默認(rèn)值缀程， 只給定一個字段搜吧，則其他字段為空
create table if not exists studentInfo2(
  `name` varchar(10),
    sex char default '男',
    age int default 18 ,
    address varchar(10) default "河南省"
    
    );
    insert into studentinfo2 (`name` , sex,age,address) values ('張三','男',28,"河南省許昌市");
    select * from studentinfo2;  -- 打印
    insert into studentinfo2 values ('張三' , '男',28,"河南省許昌市");
    -- 有默認(rèn)值的情況，可以不給定值杨凑，則值為默認(rèn)值滤奈，但是字段需要寫
    insert into studentinfo2 (`name`) values ('小愛');
    
    create table if not exists studentInfo3 (
     id int primary key auto_increment,
     `name` varchar(10),
     sex char default '男',
     age int default 18 ,
     address varchar(10) default "河南省"
     
     );
     
     insert into studentinfo3 (`name` , sex,age,address) values ( '小紅' , '女' , 19 ，"河南");
     select * from studentinfo3;
     insert into studentinfo3 (`name` , sex,age,address) values ( '小紅' , '女' , 19 撩满，"河南");
                                                                                                                            ( '小紅' , '女' , 19 蜒程，"河南");
                                                                                                                            ( '小紅' , '女' , 19 ，"河南");
                                                                                                                            ( '小紅' , '女' , 19 伺帘，"河南");
--  查詢
select * from studentinfo;
select * from studentinfo2;
select `name` , sex ,age, address from studentinfo;
select `name` , age  from  studentinfo; -- 自定義查詢的字段

-- 更新
update studentinfo2  set  age=age+1 where name = '小愛';
update studentinfo2  set  age=age+1 ;
update studentinfo2  set  age= 18 ;

-- 刪除
delete  from studentinfo where `name`="小愛";
delete  from studentinfo2;

truncate table studentinfo;